As a conventional liquid crystal display device, a device having a transverse electric field mode such as an IPS mode is used, which has, for example, pixel electrodes and a common electrode provided on an array substrate so as to make liquid crystal material fall by using a transverse electric field generated between these pixel electrodes and the common electrode.
When the common electrode is disposed on the array substrate in this way, it tends to form parasitic capacitance with respect to a signal line, thus also receiving potential change interlocking with the potential change of the signal line. Such potential change of the common electrode decreases the potential difference between a pixel electrode and a counter electrode, thereby causing degradation in image quality due to insufficient desired brightness obtained at the pixel.
Therefore, the common electrode located on the array substrate is desired to be insusceptible to the effect of potential change of a signal line.